Using Inquiry Documents After a Statutory Public Inquiry Ends

What you need to know

If you have taken part in a statutory public inquiry - whether as a core participant or a witness - you may be wondering what happens to the documents and evidence disclosed once the inquiry has finished.

In particular, people often ask whether material provided to an inquiry can later be used in civil or criminal proceedings, especially where they may be personally or professionally implicated.

A recent Supreme Court decision, Evans v Barclays Bank Plc [2025] UKSC 48, has prompted renewed focus on these issues. Although the case concerned documents from the Competition Appeal Tribunal, its reasoning is highly relevant to public inquiries and helps clarify the limits on the later use of inquiry material.

How evidence works in statutory inquiries

Statutory inquiries are governed by the Inquiries Act 2005, which sets out how evidence is obtained, handled and disclosed.

In broad terms:

• Inquiry Chairs have wide powers to manage procedure and compel the production of documents and witness evidence.
• Inquiries are generally intended to be open and transparent, with hearings held in public and documents often published on the inquiry website.
• That openness is balanced by the Chair’s powers to restrict access to evidence where necessary — for example, to protect privacy, personal data, commercial confidentiality, national security, or the effective conduct of the inquiry.
• Importantly, no one can be required to provide material that they could not be compelled to provide in ordinary civil proceedings, such as legally privileged documents.

Can inquiry documents be used in later proceedings?

Whether inquiry material can be used in later proceedings depends on how the evidence was obtained and whether any restrictions apply.

1. Section 19 restriction notices or orders

The strongest protection comes from section 19 of the Inquiries Act 2005.

• Where an inquiry Chair imposes a section 19 restriction (for example, because a document contains personal or sensitive information), that restriction continues indefinitely unless it is expressly lifted.
• Courts cannot directly override section 19 restrictions (though they can be subject to judicial review).
• Using restricted material in later proceedings would be an abuse of process.
• Breaching a section 19 order containing a penal notice can have serious consequences, including fines or imprisonment.

In practice, if a document is covered by a section 19 restriction, it is effectively off‑limits for future use.

2. Documents produced under compulsion (section 21)

Even where a section 19 restriction has not been applied, documents that are compelled - using the inquiry chair’s powers under section 21 of the Inquiries Act 2005 (under what is known as a ‘Section 21 Notice’) - are still protected.

This means that:

• Evidence obtained using statutory powers should only be used for the purpose for which those powers were exercised.
• Using compelled documents later, for different proceedings, would generally be regarded as unfair and an abuse of process. This reflects the significant intrusion involved in forcing someone to produce evidence.

3. Documents provided voluntarily

If a document:

• is not subject to a section 19 restriction; and
• was not compelled by a Section 21 Notice,

its later use is governed by the Civil Procedure Rules (CPR), particularly CPR 31.22.

In short, such documents cannot usually be used freely in later proceedings unless one of a limited number of exceptions applies - for example, where:

• the document has been read to or by the court, or referred to in a public hearing;
• the court gives permission; or
• the party who disclosed the document and the person to whom the document belongs agree.

Even then, courts retain a general power to prevent unfair or improper use of documents.

What about an Attorney General’s undertaking?

Some inquiries (including the Grenfell Tower, Post Office Horizon and Southport Inquiries) have sought an undertaking from the Attorney General.

An Attorney General’s undertaking promises that evidence given to an inquiry will not be used against the witness in a later investigation or prosecution (either generally or for specific offences).

This approach strengthens the inquiry’s ability to compel evidence, whilst providing important protection for witnesses, particularly where there may be a risk of self‑incrimination.

Can inquiry findings be relied on later?

Inquiry reports and findings raise a separate issue.

The Supreme Court’s decision in Evans v Barclays Bank Plc confirms that:

• Findings of fact or opinion from earlier proceedings are generally not admissible as evidence to prove the facts in later civil or criminal cases.
• This principle – although in this case referred to the Competition Appeal Tribunal – applies broadly and is likely to cover public inquiry reports, particularly where they contain evaluative judgments or opinions.

There is a limited exception at interlocutory stages (for example, when resisting an application for strike‑out or summary judgment), where inquiry findings may sometimes be referred to in order to show what evidence may be available. Even then, courts approach this with caution.

It is also important to remember that inquiries cannot determine individual civil or criminal liability.

Key takeaways

• Whether statutory inquiry material can be used later depends on how it was obtained and whether restrictions apply.
• Section 19 restriction orders provide the strongest protection and continue unless lifted.
• Documents produced under a Section 21 Notice are generally protected from later use.
• Inquiry reports and findings are usually inadmissible as evidence following Evans, save in very limited circumstances.
• Both core participants and witnesses who have provided documents/evidence to an inquiry, and those seeking to rely on inquiry material in future proceedings, should, however, approach these issues with care.

If you would like to discuss any of the issues raised in this article, please contact Annabel Holloway, Gemma Ludgate, Charlotte Whitaker, or any member of our Public Inquiries team.